Reinforcing member for reinforced concrete structures



Jui 12, 1938.

H. GRIVFFEL REINFORCING MEMBER FOR REINFORCED CONCRETE STRUCTURES Filed April 27, 195:5

nummnomo mm FOR REINFORCED CONCRETE 8 Henry! Grllcl, mike, Poland Application In Applications have been tiled. in Polcno on Uctober 21, 1935 and December '14, 1935 nnri. in Germany on November i l, 1M5 and December 16, 1935. I V

This invention relates to on improved reinforcing member for reinforced concrete structures.

Steel reinforcing members are already lrnown which have other than circuisr cross sections coil the uimensions of which. compared with circulur reinforcing members, are smaller the urcoteris the allowable tensile stress in relation to the tensile stress of the round cross section ol normel strength; None of the moon cross sections oi steel reinforcements can,- however, be'enchsncco for n definite corresponding clrculcr reinforcement without further colculstlons or slterution oi nlsn, us such on erchunee will only be noonhle turner the condition thotnot only is the cross Elli sectionol dimension in relotion to the lncrcuserl sllowolole stress smoller, but olso the clrcuniter ill ence of the cross section is as lsree or, or learner, tor the purpose of producing the nccessurr tenscity, than in the cone oi the corresnonuinc cireulnr reinforcement.

The present invention hw lor its oh-icct the nrooluction of cross sections of reinforcing hers consisting of high value steel oi high yield point which oreof other then circolnr torm one which .sre enchongeshle for corresponding nehnite circulur nietol bars of normel strencth without our lurther msninuletion such so colculotion or olterotion oi oion.

According to this invention, 1 nrovioe onencirculsr reinforcing member tor rclniorcecl con crete structures made oi high rnlue steel oi high rielel point hsving a cross section which is ueriverl trom the cross section oi n circle which corresn'onds to the cross section of o. normal circulur iron reinforcement and wmch is produced by removing two opposite lens-like segments ol the circle by arcs of the some rouius us, or sinsller ruoiius then, that oi the circle such thnt the ores,

' of this cross section is smelter in the neutron proportion to the area, oi the whole circle, but its periphery is at least count to or erester then the periphery of this circle. whereby a reinlorclnc member oriented for higher allowable stresses is urorluccol which is exchaneeehle directly, that is without any further calculation or ulterntlon oi plan; for the corresponding circular reinlorcine member.

The radius of the concove lcccs may. it desired, he the some as the radius oi the compendium circular reinforcing member.

can :1, 1m, sci-n1 in." 16,499 PM October :1. 1935 l Chimi- (CL 32-111) In order that the tenacity of the new reinforc lug members may not he smeliecthagn that of normal circular rods, according to the invention, all sharp edges of the respective cross-sections may be considerably rounded. Finally the crosssections of the novel reinforcing members are in appearance so different from the circular crosssections of the normal reinforcing members that then can be distinguished from the letter nt o. glance. Consequently, erroneous use of the cieo.rer reinforcing members with high strength values instead oi the normal circular reinforcements is safely avoideu. The new reinforcing members can also be provided with transverse ribs for the purpose of producing still greater tenacity or adhesion with respect to the concrete. For this purpose also the rod can he twisted. around its loneitudinsl sins;

Finally, it must be stressed that the new reini'orclnc members exhibit essentially the following advantages in comparison with the lrnown steel reiniorcements consisting of two mschine turnecl circulor rods (Isteg" system): The new reinforcing members are not, lilrethe lsteg rode.

practicable only with larger cross-sections, but

they can have the smallest CPOESTSEEUUD; their con, on account of the lack of a, special thermal the pertaining normal steel reinforcing .rnemhers of circular cross section.

in the figures r:the radius of the convert curve one. 11 the radius of the COIlCEtVG curve oi the periphery of the reinforcement, cl disrneter oi the chosen circular cross-section and s=the chord of the ore.

Reierring to the drawing, Figure 1 shows o steel reinforcing member with Ka=lllt il loci/cinhuvine two convex faces 0:, :r snci two concurs foces o, w. The member is distinguished by the simplicity of manufacture by means of rollers null in use by the shape simplifying howling one stocking. It will be seen that the greotest disinetcr c of the member corresponds eitoctir with. the diameter cl of the normal circular reinforce ments having Kz=l2tll lrgJcmfl The periphery of the member, moreover, is the some or the circumference of the circular member hut the creel is, of course, 1w. The distance i or the concave tit facesis equal to the distance h so that n=r. The cross-section according to Figure 2 differs from that according to Figure 1 principally only by the rounding of the edges of the radius 11.

In Figure 1 h=0.138'7 d and the angle c=87 14'.

In Figure 2 n=0.37 d, rz=0.065 d, h=0.1255 d, s=0.6626 d, b=0.0974 d, a=0.7064 d, the angle a=83 and the angle 19:97".

In all cases the sizes of the cross-sections formed according to the invention relative to the permissible tensile strain Kz correspond to the pertaining circular cross-sections illustrated; the peripheries are at least equal to the circumference of the respective .circular cross-section, which is advantageous from the point of view of tenacity.

In cases where a particularly great tenacity or adhesion is desired between the reinforcing member and the concrete surrounding it, the members, formed according to the invention, can be made with transverse ribs projecting from the cross-section and lying against the concrete. One embodiment of such a ribbed rod is shown in Figures 3 and 4. The cross-sectional form in Figure 3 corresponds to that in Figure 2. Between the cross section projections are arranged ribs k; the spacing can be chosen dependent on the diameter d, amounting in many cases to 1.5 d to 2 d. The size of the ribs k can be variously chosen. Obviously the invention is not limited to the form of rib shown in Figures 3 and 4.

Again, if a considerable tenacity is desired, the steel reinforcing members can be twisted about their longitudinal axis. Such a twisted reinforcing member is illustrated in Figures 5 and 6, Fig. 5 being a cross-section on the line A-A of Figure 6 and Fig. -6 being a side elevation of the reinforcing member. Such a twisting of the steel reinforcing member produces a considerable increase in the tenacity of the upper surface of the reinforcing member. 1

I claim:

1. A reinforcing member for reinforced concrete structures made of high value steel of high yield point having an approximate circular cross section with two opposite portions thereof of concave shape formed by removing two opposite lens-like segments of the same radius as that of the circular section, the periphery of the said cross section being at least equal to the periphery of said circle, whereby a reinforcing member adapted for high allowable stresses is produced which is exchangeable directly, that is without any further calculation or alteration of plan, for the corresponding circular reinforcing member.

2. A reinforcing member-for reinforced concrete structures made of high value steel of high yield point having an approximate circular cross section with two opposite portions thereof of concave shape formed by removing two opposite lens-like segments of the same radius as that of the circular section, the junction of adjacent surfaces being rounded, the periphery of the said cross section being at least equal to the periphery of said circle, whereby a-reinforcing member adapted for high allowable stresses is produced which is exchangeable directly, that is without any further calculation or alteration of plan, for

the corresponding circular reinforcing member. 3. A reinforcing member for reinforced concrete structures made of high value steel of high yield point having an approximate circular cross section with two opposite portions thereof of concave shape formed by removing two opposite lens-like segments of the same radius as that of the circular section, the periphery of the said cross section being at least equal to the periphery of said circle and said member being twisted around its axis, whereby a reinforcing member adapted for high allowable stresses is. produced which is exchangeable directly, that is without any further calculation or alteration of plan, for the corresponding circular reinforcing member. 4. A reinforcement for reinforced concrete structures comprising a reinforcing member made of high value steel of high yield point, said member having an approximate circular cross section with two opposite portions thereof of concave shape formed .by removing two opposite lens-like segments of the same radius as that of the circular section, the periphery of the said cross section being at least equal to the periphery of said circle and spaced transverse ribs on said concave portions, whereby a reinforcing member adapted for high allowable stresses is produced which is exchangeable directly, that is without any further calculation or alteration of plan, for

the corresponding circular reinforcing member.

HENRYK GRII'T'EL. 

